Pityriasis commonly refers to flaking (or scaling)
of the
skin
Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation.
Other animal coverings, such as the arthropod exoskeleton, have different ...
. The word comes from the Greek πίτυρον '
bran
Bran, also known as miller's bran, is the component of a Cereal, cereal grain consisting of the hard layersthe combined aleurone and Fruit anatomy#Pericarp layers, pericarpsurrounding the endosperm. Maize, Corn (maize) bran also includes the p ...
'.
Classification
Types include:
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Pityriasis alba, dry, fine-scaled, pale patches on the face
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Pityriasis lichenoides chronica, caused by a hypersensitivity reaction to infectious agents
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Pityriasis lichenoides et varioliformis acuta, a disease of the immune system
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Pityriasis rosea
Pityriasis rosea is a type of skin rash. Classically, it begins with a single red and slightly scaly area known as a "herald patch". This is then followed, days to weeks later, by an eruption of many smaller scaly spots; pinkish with a red edge ...
, a type of skin rash
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Pityriasis circinata,
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Pityriasis rubra pilaris, reddish-orange patches (Latin: ''rubra'') on the skin
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Pityriasis versicolor, a skin eruption on the trunk and proximal extremities, usually caused by a fungus
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Dandruff
Dandruff is a skin condition of the scalp. Symptoms include flaking and sometimes mild itchiness. It can result in social or self-esteem problems. A more severe form of the condition, which includes inflammation of the skin, is known as s ...
, historically called ''Pityriasis capitis''
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Pityriasis amiantacea, condition of the scalp in which thick tenaciously adherent scale infiltrates and surrounds the base of a group of scalp hairs
See also
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Desquamation
Desquamation, or peeling skin, is the shedding of dead cells from the outermost layer of skin.
The term is .
Physiologic desquamation
Keratinocytes are the predominant cells of the epidermis, the outermost layer of the skin. Living keratin ...
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List of cutaneous conditions
Many skin conditions affect the human integumentary system—the organ system covering the entire surface of the Human body, body and composed of Human skin, skin, hair, Nail (anatomy), nails, and related muscle and glands. The major function o ...
References
External links
Dermatologic terminology
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